<html>
  <link rel="stylesheet" href="seamless-iframe.css">
  <body>
    <script>
      var iframe = document.createElement('iframe');
      iframe.className = 'seamless';
      document.body.appendChild(iframe);
      var doc = iframe.contentDocument;
      doc.open();
      doc.write('<html><body>Hello, world!</body></html>');
      doc.close();
    </script>
  </body>
</html>
